1. Field of the Invention
The present invention concerns joints utilized in structures. Even more particularly, the present invention concerns larger vertical joints in curtain wall applications allowing expansion and contraction of the wall substrate while maintaining a water-tight seal.
2. Description of the Prior Art
In the construction of buildings and roads having multiple panels therein, there has long existed the need for joints and other similar means to connect substrates and accommodate the expansion of these substrates due to thermal conditions. Such joints used in highways have been termed horizontal joints. Those utilized in buildings, notably in skyscrapers, have been termed vertical joints. Those joints within buildings which interconnect with vertical joints or other vertical members are termed vertical-horizontal joints.
In selecting among the known materials to form a vertical joint, architects have heretofore abstained from using silicone sealants. This has been due to the size of the joints, usually over 3/4 inch in width and often 1 and 1/4 inches or more. Silicone is normally applied wet in this type of joint. Before solidifying, the silicone would readily sag and slump within the joint. This produced an uneven joint, which could not perform in the needed manner nor insure a watertight seal.
Architects therefore turned to other materials, most notably rubber and neoprine. These natural products perform the necessary task a joint must. However, joints made from these materials suffer from drawbacks. Firstly, the cost of these materials is high. Additionally, the labor necessary to construct these joints is great, and these joints often require plates or other similar support structures therein. Further, the joints effected with these materials are often aesthetically unpleasing. Finally and most importantly, these materials deteriorate with exposure to the elements, particularly to ultraviolet light which is contained with sunlight. That these materials have a somewhat limited lifespan is marked by the industry warranties of these materials in such joints for a maximum of five years.
Silicone offers a jointing material that is relatively unaffected by ultraviolet light and exposure to the elements. It is also a very resilient material, thus quite suited for work in a joint. Industry warranties of twenty years attest to the durability and desirability of silicon in joints. Therefore, there exists a need in the construction arts for a device to effect a vertical joint comprising silicone, as well as a need for a vertical silicone joint, particularly in but not limited to large-scale construction.
An example of a common method known to those skilled in the art to effect joints is set forth in U.S. Pat. No. 3,334,557 issued Aug. 8, 1967 to Fitzgibbon and is entitled "POLYURETHANE CONCRETE SLAB SEALER". Fitzgibbon teaches the filling of a gap between concrete slabs in a roadway with plastic polyurethane liquid materials to provide a horizontal joint. The liquid material expands after placement and expands to a volume that fills the gap. The deployment of the liquid sealant, in situ, affords full coverage of space while affording a waterproof material.
However, problems result if such a system is attempted in a vertical setting. Firstly, there are problems in pouring or applying the liquid sealant. Devices or mold structures to prevent the run-off of the sealant due to gravity, such as boards over the gap or opening, would have to be developed. Time must be spent assembling and later disassembling these mold structures. These devices would not, however, address the problems of even distribution of the silicone sealant. Further, time is lost while allowing the sealant to dry. Finally, finishing processes must be applied to complete the joint.
A vertical joint is found in U.S. Pat. No. 4,058,947 issued to Nov. 22, 1977 to Earle et alia and is entitled "FIRE RESISTANT JOINT SYSTEM FOR CONCRETE STRUCTURES". Earle teaches a joint comprising a refractory fiber mass which is wedged in the gap between adjacent concrete panels. Frictional forces hold the fiber mass within the gap. A backup component is deployed atop the fiber mass. Atop this backup component is deployed the sealant. The sealant is disposed and dried in contact with the backup component and the concrete panels.
The Earle patent does not provide connection between the fiber mass and the sealant. Thus, the mass can be dislodged as the panels contract and expand. Further, this lack of connection does not give any backing to the sealant, which could be torn or otherwise broken by the movement of the building. Thus, the joint of Earle can fail during use.
It is unknown in the art, to the best of the Applicant's knowledge, to effect a vertical joint utilizing silicone, and particularly of joints of the size commonly found in large-scale construction. It is to these needs that the present invention is directed.